Unofficial Bevy Cheat Book

This is a reference-style book for the Bevy game engine (GitHub).

It aims to teach Bevy concepts in a concise way, help you be productive, and discover the knowledge you need.

This book aggregates a lot of community wisdom that is often not covered by official documentation, saving you the need to struggle with issues that others have figured out already!

While it aims to be exhaustive, documenting an entire game engine is a monumental task. I focus my time on whatever I believe the community needs most.

Therefore, there are still a lot of omissions, both for basics and advanced topics. Nevertheless, I am confident this book will prove to be a valuable resource to you!

Welcome! May this book serve you well!

(don't forget to Star the book's GitHub repository, and consider donating 🙂)

How to use this book

The pages in this book are not designed to be read in order. Each page covers a standalone topic. Feel free to jump to whatever interests you.

If you have a specific topic in mind that you would like to learn about, you can find it from the table-of-contents (sidebar) or using the search function (in the top bar).

The Chapter Overview page will give you a general idea of how the book is structured.

If you are new to Bevy, or would like a more guided experience, try the tutorial page. It will help you navigate the book in an order that makes sense for learning, from beginner to advanced topics.

The Bevy Builtins page is a concise cheatsheet of useful information about types and features provided by Bevy.

Recommended Additional Resources

Bevy has a rich collection of official code examples.

Check out bevy-assets, for community-made resources.

Our community is very friendly and helpful. Feel welcome to join the Bevy Discord to chat, ask questions, or get involved in the project!

If you want to see some games made with Bevy, see itch.io or Bevy Assets.

Support Me

GitHub Sponsors

I'd like to keep improving and maintaining this book, to provide a high-quality independent learning resource for the Bevy community.

Your donation helps me work on such freely-available content. Thank you! ❤️

Support Bevy

GitHub Sponsors

If you like the Bevy Game Engine, you should consider donating to the project.

To ease the maintenance burden, the policy of the project is that the book may contain a mixture of content for different versions of Bevy. However, mixing outdated and updated content on the same page is not allowed.

Every page in the book must clearly state what version of Bevy it was written for, at the top of the page, above the main heading. All content on that page must be relevant for the stated Bevy version.

Current Bevy Version

The current Bevy release is 0.10.

The aim is to try to maintain the book up to date with the current latest release of Bevy. New content should be written for this version. Outdated pages will be updated on a best-effort basis.

Old Bevy Version

Content for old releases of Bevy is only allowed in the book if it already exists from before and has not been updated yet.

Unreleased (Bevy's git main branch)

Pages that cover new yet-unreleased features of Bevy are allowed. If there is an exciting new feature, and I want to document it, I will write a page, without waiting for the next release of Bevy to come out. :)

For functionality that exists in the current release in some form, but has changed for the next release, the current version is the one that should be documented. The page can be updated in the future. I might sometimes make exceptions to this rule.

License

All code in the book is provided under the MIT-0 License. At your option, you may also use it under the regular MIT License.

The text of the book is provided under the CC BY-NC-SA 4.0.

Exception: If used for the purpose of contribution to the "Official Bevy Project", the entire content of the book may be used under the MIT-0 License.

"Official Bevy Project" is defined as:

Contents of the Git repository hosted at https://github.com/bevyengine/bevy
Contents of the Git repository hosted at https://github.com/bevyengine/bevy-website
Anything publicly visible on the bevyengine.org website

The MIT-0 license applies as soon as your contribution has been accepted upstream.

GitHub Forks and Pull Requests created for the purposes of contributing to the Official Bevy Project are given the following license exception: the Attribution requirements of CC BY-NC-SA 4.0 are waived for as long as the work is pending upstream review (Pull Request Open). If upstream rejects your contribution, you are given a period of 1 month to comply with the full terms of the CC BY-NC-SA 4.0 license or delete your work. If upstream accepts your contribution, the MIT-0 license applies.

Contributions

Development of this book is hosted on GitHub.

Please file GitHub Issues for any wrong/confusing/misleading information, as well as suggestions for new content you'd like to be added to the book.

Contributions are accepted, with some limitations.

See the Contributing section for all the details.

Stability Warning

Bevy is still a new and experimental game engine! It has only been public since August 2020!

While improvements have been happening at an incredible pace, and development is active, Bevy simply hasn't yet had the time to mature.

There are no stability guarantees and breaking changes happen often!

Usually, it not hard to adapt to changes with new releases, but you have been warned!